This proposal addresses the need, identified by the National Institute on Deafness and Other Communication Disorders, for the "Adaptation of multiple array electrodes for use in chemosensory electrophysiological studies". The goal is the development of a biologically-based olfactant recognition system. A 100-electrode array will be modified to provide tools and techniques that can be used by neuroscientists in the investigation of the olfactory system. These tools will also provide the basis for the development of implanted animals in the detection of explosives and drugs of abuse by the military and the law enforcement communities. Phase I will demonstrate the feasibility of using these arrays as the basis for tools and techniques for the electrophysiological study of the olfactory bulb. Acute implantation in rats will verify that olfactant-driven responses can be recorded, and the use of simultaneous recordings from large populations of neurons in olfactory bulb will be investigated for their potential application to discriminating olfactants. Phase II will further develop these tools to study whether simultaneous recordings from large numbers of spiking neurons in the olfactory bulb can be used to reliably discriminate between a large variety of olfactants. PROPOSED COMMERCIAL APPLICATIONS: The chronic and acute systems will be marketed to researchers worldwide for the investigation of olfactory processes using animal subjects such as rats and dogs. The system will also be adapted to implantation in animals for the detection of explosives and drugs of abuse by the military and the law enforcement communities